[OpenAFS-devel] suggested feature...

[Neulinger, Nathan]

I've been noticing recently that the filesystem overhead is getting larger
(not specific to afs, just different filesystems, and larger cache sizes).
I've had several systems recently complain about the cache partition being
full, due to it actually filling up, even though I've left a sizable amount
free (cacheinfo sized less than the actual partition size), but obviously
not enough. (my overhead calculation obviously isn't sufficient any more,
and needed adjusting)

I'd agree, it shouldn't happen, but if you accidentally undersize the
partition (or in my case, realize that the overhead calculation previously
used is no longer sufficient), it would be nice if the cache manager could
more gracefully handle that situation.

I just wonder how hard it would be for it to have something like:

Existing:
	if cache-free-space-according-to-cacheinfo-and-cache-entry-sizes <
sizeof-new-chunk-needed
		flush some cache entries
Added code:
	elsif actual-cache-free-space < sizeof-new-chunk-needed
		flush some cache entries


-- Nathan

> -----Original Message-----
> From: Derek Atkins [mailto:warlord@MIT.EDU]
> Sent: Tuesday, September 25, 2001 9:41 AM
> To: Neulinger, Nathan
> Cc: 'openafs-devel@openafs.org'
> Subject: Re: [OpenAFS-devel] suggested feature...
> 
> 
> This is never a problem if your cache is on its own partition and you
> tell the cache manager what size the partition is.  In fact, that
> is the recommended operating procedure.  What are you doing? ;)
> 
> -derek
> 
> "Neulinger, Nathan" <nneul@umr.edu> writes:
> 
> > Would be nice if the cache manager could handle a 
> cache-partition full
> > situation more gracefully - i.e. if it's full, 
> automatically shrink the
> > cache size internally and free stuff up.
> > 
> > -- Nathan
> > 
> > ------------------------------------------------------------
> > Nathan Neulinger                       EMail:  nneul@umr.edu
> > University of Missouri - Rolla         Phone: (573) 341-4841
> > Computing Services                       Fax: (573) 341-4216
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> > OpenAFS-devel@openafs.org
> > https://lists.openafs.org/mailman/listinfo/openafs-devel
> 
> -- 
>        Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
>        Member, MIT Student Information Processing Board  (SIPB)
>        URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
>        warlord@MIT.EDU                        PGP key available
>